SYNOPSIS

DESCRIPTION

The graph function of RRDtool is used to present the data from an RRD
to a human viewer. Its main purpose is to create a nice graphical
representation, but it can also generate a numerical report.

OVERVIEW

rrdtoolgraph needs data to work with, so you must use one or more datadefinition statements to collect this data. You are not limited to one
database, it's perfectly legal to collect data from two or more
databases (one per statement, though).
If you want to display averages, maxima, percentiles, etcetera it is
best to collect them now using the variabledefinition statement.
Currently this makes no difference, but in a future version of RRDtool
you may want to collect these values before consolidation.
The data fetched from the RRA is then consolidated so that there is
exactly one data point per pixel in the graph. If you do not take care
yourself, RRDtool will expand the range slightly if necessary. Note, in
that case the first and/or last pixel may very well become unknown!
Sometimes data is not exactly in the format you would like to display
it. For instance, you might be collecting bytes per second, but want to
display bits per second. This is what the datacalculation command is
designed for. After consolidating the data, a copy is made and this
copy is modified using a rather powerful RPN command set.
When you are done fetching and processing the data, it is time to graph
it (or print it). This ends the rrdtoolgraph sequence.
Use graphv instead of graph to get detailed information about the graph
geometry and data once it is drawn. See the bottom of the document for
more information.

OPTIONS

filename
The name and path of the graph to generate. It is recommended to end
this in ".png", ".svg" or ".eps", but RRDtool does not enforce this.
filename can be '"-"' to send the image to "stdout". In this case, no
other output is generated.
Timerange
[-s|--starttime] [-e|--endtime] [-S|--stepseconds]
The start and end of the time series you would like to display, and
which RRA the data should come from. Defaults are: 1 day ago until
now, with the best possible resolution. Start and end can be specified
in several formats, see AT-STYLE TIME SPECIFICATION and
rrdgraph_examples. By default, rrdtoolgraph calculates the width of
one pixel in the time domain and tries to get data from an RRA with
that resolution. With the step option you can alter this behavior. If
you want rrdtoolgraph to get data at a one-hour resolution from the
RRD, set step to 3'600. Note: a step smaller than one pixel will
silently be ignored.
Labels
[-t|--titlestring] [-v|--vertical-labelstring]
A horizontal string at the top of the graph and/or a vertically placed
string at the left hand side of the graph.
Size
[-w|--widthpixels] [-h|--heightpixels] [-j|--only-graph]
[-D|--full-size-mode]
By default, the width and height of the canvas (the part with the
actual data and such). This defaults to 400 pixels by 100 pixels.
If you specify the --full-size-mode option, the width and height
specify the final dimensions of the output image and the canvas is
automatically resized to fit.
If you specify the --only-graph option and set the height < 32 pixels
you will get a tiny graph image (thumbnail) to use as an icon for use
in an overview, for example. All labeling will be stripped off the
graph.
Limits
[-u|--upper-limitvalue] [-l|--lower-limitvalue] [-r|--rigid]
By default the graph will be autoscaling so that it will adjust the
y-axis to the range of the data. You can change this behavior by
explicitly setting the limits. The displayed y-axis will then range at
least from lower-limit to upper-limit. Autoscaling will still permit
those boundaries to be stretched unless the rigid option is set.
[-A|--alt-autoscale]
Sometimes the default algorithm for selecting the y-axis scale is not
satisfactory. Normally the scale is selected from a predefined set of
ranges and this fails miserably when you need to graph something like
"260 + 0.001 * sin(x)". This option calculates the minimum and maximum
y-axis from the actual minimum and maximum data values. Our example
would display slightly less than "260-0.001" to slightly more than
"260+0.001" (this feature was contributed by Sasha Mikheev).
[-J|--alt-autoscale-min]
Where "--alt-autoscale" will modify both the absolute maximum AND
minimum values, this option will only affect the minimum value. The
maximum value, if not defined on the command line, will be 0. This
option can be useful when graphing router traffic when the WAN line
uses compression, and thus the throughput may be higher than the WAN
line speed.
[-M|--alt-autoscale-max]
Where "--alt-autoscale" will modify both the absolute maximum AND
minimum values, this option will only affect the maximum value. The
minimum value, if not defined on the command line, will be 0. This
option can be useful when graphing router traffic when the WAN line
uses compression, and thus the throughput may be higher than the WAN
line speed.
[-N|--no-gridfit]
In order to avoid anti-aliasing blurring effects RRDtool snaps points
to device resolution pixels, this results in a crisper appearance. If
this is not to your liking, you can use this switch to turn this
behavior off.
Grid-fitting is turned off for PDF, EPS, SVG output by default.
X-Axis
[-x|--x-gridGTM:GST:MTM:MST:LTM:LST:LPR:LFM]
[-x|--x-gridnone]
The x-axis label is quite complex to configure. If you don't have very
special needs it is probably best to rely on the auto configuration to
get this right. You can specify the string "none" to suppress the grid
and labels altogether.
The grid is defined by specifying a certain amount of time in the ?TM
positions. You can choose from "SECOND", "MINUTE", "HOUR", "DAY",
"WEEK", "MONTH" or "YEAR". Then you define how many of these should
pass between each line or label. This pair (?TM:?ST) needs to be
specified for the base grid (G??), the major grid (M??) and the labels
(L??). For the labels you also must define a precision in LPR and a
strftime format string in LFM. LPR defines where each label will be
placed. If it is zero, the label will be placed right under the
corresponding line (useful for hours, dates etcetera). If you specify
a number of seconds here the label is centered on this interval (useful
for Monday, January etcetera).
--x-grid MINUTE:10:HOUR:1:HOUR:4:0:%X
This places grid lines every 10 minutes, major grid lines every hour,
and labels every 4 hours. The labels are placed under the major grid
lines as they specify exactly that time.
--x-grid HOUR:8:DAY:1:DAY:1:86400:%A
This places grid lines every 8 hours, major grid lines and labels each
day. The labels are placed exactly between two major grid lines as they
specify the complete day and not just midnight.
Y-Axis
[-y|--y-gridgridstep:labelfactor]
[-y|--y-gridnone]
Y-axis grid lines appear at each gridstep interval. Labels are placed
every labelfactor lines. You can specify "-y none" to suppress the
grid and labels altogether. The default for this option is to
automatically select sensible values.
If you have set --y-grid to 'none' not only the labels get suppressed,
also the space reserved for the labels is removed. You can still add
space manually if you use the --units-length command to explicitly
reserve space.
[-Y|--alt-y-grid]
Place the Y grid dynamically based on the graph's Y range. The
algorithm ensures that you always have a grid, that there are enough
but not too many grid lines, and that the grid is metric. That is the
grid lines are placed every 1, 2, 5 or 10 units. This parameter will
also ensure that you get enough decimals displayed even if your graph
goes from 69.998 to 70.001. (contributed by Sasha Mikheev).
[-o|--logarithmic]
Logarithmic y-axis scaling.
[-X|--units-exponentvalue]
This sets the 10**exponent scaling of the y-axis values. Normally,
values will be scaled to the appropriate units (k, M, etc.). However,
you may wish to display units always in k (Kilo, 10e3) even if the data
is in the M (Mega, 10e6) range, for instance. Value should be an
integer which is a multiple of 3 between -18 and 18 inclusively. It is
the exponent on the units you wish to use. For example, use 3 to
display the y-axis values in k (Kilo, 10e3, thousands), use -6 to
display the y-axis values in u (Micro, 10e-6, millionths). Use a value
of 0 to prevent any scaling of the y-axis values.
This option is very effective at confusing the heck out of the default
RRDtool autoscaling function and grid painter. If RRDtool detects that
it is not successful in labeling the graph under the given
circumstances, it will switch to the more robust --alt-y-grid mode.
[-L|--units-lengthvalue]
How many digits should RRDtool assume the y-axis labels to be? You may
have to use this option to make enough space once you start fiddling
with the y-axis labeling.
[--units=si]
With this option y-axis values on logarithmic graphs will be scaled to
the appropriate units (k, M, etc.) instead of using exponential
notation. Note that for linear graphs, SI notation is used by default.
RightYAxis
[--right-axisscale:shift] [--right-axis-labellabel]
A second axis will be drawn to the right of the graph. It is tied to
the left axis via the scale and shift parameters. You can also define a
label for the right axis.
[--right-axis-formatformat-string]
By default the format of the axis labels gets determined automatically.
If you want to do this your self, use this option with the same %lf
arguments you know from the PRINT and GPRINT commands.
Legend
[-g|--no-legend]
Suppress generation of the legend; only render the graph.
[-F|--force-rules-legend]
Force the generation of HRULE and VRULE legends even if those HRULE or
VRULE will not be drawn because out of graph boundaries (mimics
behavior of pre 1.0.42 versions).
[--legend-position=(north|south|west|east)]
Place the legend at the given side of the graph. The default is south.
In west or east position it is necessary to add line breaks manually.
[--legend-direction=(topdown|bottomup)]
Place the legend items in the given vertical order. The default is
topdown. Using bottomup the legend items appear in the same vertical
order as a stack of lines or areas.
Miscellaneous
[-z|--lazy]
Only generate the graph if the current graph is out of date or not
existent. Note, that all the calculations will happen regardless so
that the output of PRINT and graphv will be complete regardless. Note
that the behavior of lazy in this regard has seen several changes over
time. The only thing you can really rely on before RRDtool 1.3.7 is
that lazy will not generate the graph when it is already there and up
to date, and also that it will output the size of the graph.
[--daemonaddress]
Address of the rrdcached daemon. If specified, a "flush" command is
sent to the server before reading the RRD files. This allows the graph
to contain fresh data even if the daemon is configured to cache values
for a long time. For a list of accepted formats, see the -l option in
the rrdcached manual.
rrdtool graph [...] --daemon unix:/var/run/rrdcached.sock [...]
[-f|--imginfoprintfstr]
After the image has been created, the graph function uses printf
together with this format string to create output similar to the PRINT
function, only that the printf function is supplied with the parameters
filename, xsize and ysize. In order to generate an IMG tag suitable for
including the graph into a web page, the command line would look like
this:
--imginfo '<IMG SRC="/img/%s" WIDTH="%lu" HEIGHT="%lu" ALT="Demo">'
[-c|--colorCOLORTAG#rrggbb[aa]]
Override the default colors for the standard elements of the graph. The
COLORTAG is one of "BACK" background, "CANVAS" for the background of
the actual graph, "SHADEA" for the left and top border, "SHADEB" for
the right and bottom border, "GRID", "MGRID" for the major grid, "FONT"
for the color of the font, "AXIS" for the axis of the graph, "FRAME"
for the line around the color spots, and finally "ARROW" for the arrow
head pointing up and forward. Each color is composed out of three
hexadecimal numbers specifying its rgb color component (00 is off, FF
is maximum) of red, green and blue. Optionally you may add another
hexadecimal number specifying the transparency (FF is solid). You may
set this option several times to alter multiple defaults.
A green arrow is made by: "--color ARROW#00FF00"
[--grid-dashon:off]
by default the grid is drawn in a 1 on, 1 off pattern. With this option
you can set this yourself
--grid-dash 1:3 for a dot grid
--grid-dash 1:0 for uninterrupted grid lines
[--borderwidth]]
Width in pixels for the 3d border drawn around the image. Default 2, 0
disables the border. See "SHADEA" and "SHADEB" above for setting the
border color.
[--dynamic-labels]
Pick the shape of the color marker next to the label according to the
element drawn on the graph.
[-m|--zoomfactor]
Zoom the graphics by the given amount. The factor must be > 0
[-n|--fontFONTTAG:size:[font]]
This lets you customize which font to use for the various text elements
on the RRD graphs. "DEFAULT" sets the default value for all elements,
"TITLE" for the title, "AXIS" for the axis labels, "UNIT" for the
vertical unit label, "LEGEND" for the graph legend, "WATERMARK" for the
watermark on the edge of the graph.
Use Times for the title: "--font TITLE:13:Times"
Note that you need to quote the argument to --font if the font-name
contains whitespace: --font "TITLE:13:Some Font"
If you do not give a font string you can modify just the size of the
default font: "--font TITLE:13:".
If you specify the size 0 then you can modify just the font without
touching the size. This is especially useful for altering the default
font without resetting the default fontsizes: "--font
DEFAULT:0:Courier".
RRDtool comes with a preset default font. You can set the environment
variable "RRD_DEFAULT_FONT" if you want to change this.
RRDtool uses Pango for its font handling. This means you can to use the
full Pango syntax when selecting your font:
The font name has the form "[FAMILY-LIST] [STYLE-OPTIONS] [SIZE]",
where FAMILY-LIST is a comma separated list of families optionally
terminated by a comma, STYLE_OPTIONS is a whitespace separated list of
words where each WORD describes one of style, variant, weight, stretch,
or gravity, and SIZE is a decimal number (size in points) or optionally
followed by the unit modifier "px" for absolute size. Any one of the
options may be absent.
[-R|--font-render-mode {normal,light,mono}]
There are 3 font render modes:
normal: Full Hinting and Anti-aliasing (default)
light: Slight Hinting and Anti-aliasing
mono: Full Hinting and NO Anti-aliasing
[-B|--font-smoothing-thresholdsize]
(this gets ignored in 1.3 for now!)
This specifies the largest font size which will be rendered bitmapped,
that is, without any font smoothing. By default, no text is rendered
bitmapped.
[-P|--pango-markup]
All text in RRDtool is rendered using Pango. With the --pango-markup
option, all text will be processed by pango markup. This allows to
embed some simple html like markup tags using
<span key="value">text</span>
Apart from the verbose syntax, there are also the following short tags
available.
b Bold
big Makes font relatively larger, equivalent to <span size="larger">
i Italic
s Strikethrough
sub Subscript
sup Superscript
small Makes font relatively smaller, equivalent to <span size="smaller">
tt Monospace font
u Underline
More details on
<http://developer.gnome.org/doc/API/2.0/pango/PangoMarkupFormat.html>.
[-G|--graph-render-mode {normal,mono}]
There are 2 render modes:
normal: Graphs are fully Anti-aliased (default)
mono: No Anti-aliasing
[-E|--slope-mode]
RRDtool graphs are composed of stair case curves by default. This is in
line with the way RRDtool calculates its data. Some people favor a more
'organic' look for their graphs even though it is not all that true.
[-a|--imgformatPNG|SVG|EPS|PDF]
Image format for the generated graph. For the vector formats you can
choose among the standard Postscript fonts Courier-Bold, Courier-
BoldOblique, Courier-Oblique, Courier, Helvetica-Bold, Helvetica-
BoldOblique, Helvetica-Oblique, Helvetica, Symbol, Times-Bold, Times-
BoldItalic, Times-Italic, Times-Roman, and ZapfDingbats.
[-i|--interlaced]
(this gets ignored in 1.3 for now!)
If images are interlaced they become visible on browsers more quickly.
[-T|--tabwidthvalue]
By default the tab-width is 40 pixels, use this option to change it.
[-b|--basevalue]
If you are graphing memory (and NOT network traffic) this switch should
be set to 1024 so that one Kb is 1024 byte. For traffic measurement, 1
kb/s is 1000 b/s.
[-W|--watermarkstring]
Adds the given string as a watermark, horizontally centered, at the
bottom of the graph.
DataandvariablesDEF:vname=rrdfile:ds-name:CF[:step=step][:start=time][:end=time]
CDEF:vname=RPNexpressionVDEF:vname=RPNexpression
You need at least one DEF and one LINE, AREA, GPRINT, PRINT statement
to generate anything useful.
See rrdgraph_data and rrdgraph_rpn for the exact format.
NOTE: Graphandprintelements
You need at least one graph element to generate an image and/or at
least one print statement to generate a report. See rrdgraph_graph for
the exact format.
graphv
Calling RRDtool with the graphv option will return information in the
RRDtool info format. On the command line this means that all output
will be in key=value format. When used from the Perl and Ruby bindings
a hash pointer will be returned from the call.
When the filename '-' is given, the contents of the graph itself will
also be returned through this interface (hash key 'image'). On the
command line the output will look like this:
print[0] = "0.020833"
print[1] = "0.0440833"
graph_left = 51
graph_top = 22
graph_width = 400
graph_height = 100
graph_start = 1232908800
graph_end = 1232914200
image_width = 481
image_height = 154
value_min = 0.0000000000e+00
value_max = 4.0000000000e-02
image = BLOB_SIZE:8196
[... 8196 bytes of image data ...]
There is more information returned than in the standard interface.
Especially the 'graph_*' keys are new. They help applications that want
to know what is where on the graph.

ENVIRONMENTVARIABLES

The following environment variables may be used to change the behavior
of "rrdtool graph":
RRDCACHED_ADDRESS
If this environment variable is set it will have the same effect as
specifying the "--daemon" option on the command line. If both are
present, the command line argument takes precedence.

SEEALSO

rrdgraph gives an overview of how rrdtoolgraph works. rrdgraph_data
describes DEF,CDEF and VDEF in detail. rrdgraph_rpn describes the RPN
language used in the ?DEF statements. rrdgraph_graph page describes
all of the graph and print functions.
Make sure to read rrdgraph_examples for tips&tricks.